We have observed that body weight of rats was decreased after administration of the metabolites of 3,4-methyledioxyamphetamine (MDA) and N-methyl-3,4-methylenedixoyamphetamine (MDMA) during a study of the neurochemical effects of MDA and MDMA, analogues of amphetamine and methylamphetamine, respectively. Preliminary results of the anorexia of MDMA, N-ethyl-3,4-methylenedioxyamphetamine (MDEA), amphetamine, 4- hydroxyamphetamine, phenylpropanolamine, phenylephrine, sigma- methyldopamine, sigma-methylepinephrine, sigma-methylnorepinephrine have been obtained in 1992. Additional experimental data on anorectic effect of these compounds in rats have been collected. Furthermore, the anorectic and stimulatory effects of metaraminol has been studied. From the results of these studies the following conclusions may be drawn: 1) Anorectic potency of MDMA and MDEA are comparable to that of amphetamine. 2) Anorectic potency of monohydroxy derivatives of amphetamine, such as 4-hydroxyamphetamine and phenylpropanolamine, decreased as compared to that of amphetamine. 3) The anorectic potency of dihydroxy derivatives of amphetamine, such as phenylephrine, is higher than that of monohydroxy derivative of amphetamine and comparable to that of amphetamine. 4) The anorectic potency of three hydroxy derivatives of amphetamine and methamphetamine, such as sigma-methylepinephrine and sigma- methylnorepinephrine, respectively, are potent and long last than that of amphetamine. Stimulatory activity of hydroxylated derivatives of amphetamine is less than that of amphetamine. Application for patent for sigma-methylepinephrine, sigma-methylnorepinephrine and metaraminol for use as anorectic agents and treatment of obesity has been filed.